This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A229754 Number of defective 4-colorings of an n X 7 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..3 order. 1
 210, 20032, 41872, 69198, 113330, 186396, 314700, 557578, 1046550, 2070144, 4258696, 8984046, 19221426, 41402836, 89392212, 192991026, 416096878, 895389192, 1922585088, 4119014998, 8805491466, 18784661532, 39993300364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 9*a(n-1) - 33*a(n-2) + 63*a(n-3) - 66*a(n-4) + 36*a(n-5) - 8*a(n-6) for n>11. Empirical g.f.: 2*x*(105 + 9071*x - 65743*x^2 + 170088*x^3 - 187916*x^4 + 63288*x^5 + 30816*x^6 - 21756*x^7 - 2936*x^8 + 504*x^9 + 1360*x^10) / ((1 - x)^3*(1 - 2*x)^3). - Colin Barker, Sep 21 2018 EXAMPLE Some solutions for n=3: ..0..1..0..0..2..0..1....0..1..0..2..3..0..1....0..1..0..2..3..2..1 ..2..3..2..3..1..3..2....2..3..3..1..1..2..3....3..2..3..1..0..1..3 ..1..0..2..0..2..0..1....0..1..2..0..3..0..1....0..1..0..2..3..2..1 CROSSREFS Column 7 of A229755. Sequence in context: A140904 A092711 A187308 * A089514 A289328 A014979 Adjacent sequences:  A229751 A229752 A229753 * A229755 A229756 A229757 KEYWORD nonn AUTHOR R. H. Hardin, Sep 28 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 17 09:23 EST 2018. Contains 318193 sequences. (Running on oeis4.)